feat: add progress indication for long downloads

hooks/use-progress.tsx

@@ -0,0 +1,85 @@
+import { useEffect, useState } from "react"
+
+interface Progress {
+  id: string
+  current: number
+  total: number
+  type: string
+  data: any
+  createdAt: string
+}
+
+interface UseProgressOptions {
+  onSuccess?: (progress: Progress) => void
+  onError?: (error: Error) => void
+}
+
+export function useProgress(options: UseProgressOptions = {}) {
+  const [isLoading, setIsLoading] = useState(false)
+  const [eventSource, setEventSource] = useState<EventSource | null>(null)
+  const [progress, setProgress] = useState<Progress | null>(null)
+
+  // Cleanup on unmount
+  useEffect(() => {
+    return () => {
+      if (eventSource) {
+        eventSource.close()
+      }
+    }
+  }, [eventSource])
+
+  const startProgress = async (type: string) => {
+    setIsLoading(true)
+    setProgress(null)
+
+    // Close any existing connection
+    if (eventSource) {
+      eventSource.close()
+    }
+
+    try {
+      const progressId = crypto.randomUUID()
+      const source = new EventSource(`/api/progress/${progressId}?type=${type}`)
+      setEventSource(source)
+
+      source.onmessage = (event) => {
+        try {
+          const progress = JSON.parse(event.data)
+          setProgress(progress)
+          options.onSuccess?.(progress)
+
+          if (progress.current === progress.total && progress.total > 0) {
+            source.close()
+            setIsLoading(false)
+          }
+        } catch (error) {
+          console.error("Failed to parse progress data:", error)
+          source.close()
+          setIsLoading(false)
+        }
+      }
+
+      source.onerror = (error) => {
+        source.close()
+        setIsLoading(false)
+        const err = new Error("Progress tracking failed")
+        console.error("Progress tracking error:", err)
+        options.onError?.(err)
+      }
+
+      return progressId
+    } catch (error) {
+      setIsLoading(false)
+      const err = error instanceof Error ? error : new Error("Failed to start progress")
+      console.error("Failed to start progress:", err)
+      options.onError?.(err)
+      return null
+    }
+  }
+
+  return {
+    isLoading,
+    startProgress,
+    progress,
+  }
+}